Saturated aliphatic carbon atoms

Hydroxylation of saturated aliphatic carbon atoms. The saturated aliphatic carbons hydroxylated by cytochromes... 

Alcohols and phenols contain the hydroxyl group (—O—H) as their functional group. Alcohols may be considered to be derived from saturated or unsaturated hydrocarbons by the replacement of at least one H atom by a hydroxyl group. The properties of alcohols result from a hydroxyl group attached to an aliphatic carbon atom, —C—O—H. Ethanol (ethyl alcohol) is the most common example (Figure 27-14). 

A tertiary or quaternary carbon atom is an atom of which 3 or 4 valencies, respectively, are saturated by carbon atoms, at least one of them being aliphatic a, p, y etc. denote the position of the C atoms with respect to the oxygen group. 

Amyl alcohol describes any saturated aliphatic alcohol containing five carbon atoms. This class consists of three pentanols, four substituted butanols, and a disubstituted propanol, ie, eight stmctural isomers four primary, three secondary, and one tertiary alcohol. In addition, 2-pentanol,... 

In general, substituents removed from the ring by two or more saturated carbon atoms undergo normal aliphatic reactions, and substituents attached directly to fused benzene rings or aryl groups undergo the same reactions as do those on normal benzenoid rings. 

Carboxylic acid groups can be detected by both and A3C NMR spectroscopy. Carboxyl carbon atoms absorb in the range 165 to 185 8 in the l3C NMR spectrum, with aromatic and unsaturated acids near the upheld end of the range (—165 8) and saturated aliphatic acids near the downfield end (—185 8). Nitrile carbons absorb in the range 115 to 130 8. 

Volume 8 Volume 9 Volume 10 Volume 12 Volume 13 Proton Transfer Addition and Elimination Reactions of Aliphatic Compounds Ester Formation and Hydrolysis and Related Reactions Electrophilic Substitution at a Saturated Carbon Atom Reactions of Aromatic Compounds Section 5. POLYMERISATION REACTIONS (3 volumes)... 

Several distinct mechanisms are possible for aliphatic nucleophilic substitution reactions, depending on the substrate, nucleophile, leaving group, and reaction conditions. In all of them, however, the attacking reagent carries the electron pair with it, so that the similarities are greater than the differences. Mechanisms that occur at a saturated carbon atom are considered first. By far the most common are the SnI and Sn2 mechanisms. 

In reality all carbon atoms share equally the pool of electrons which constitute the double bonds and benzene resists addition across the double bonds which would otherwise destroy its unique structure and stability. Single or multiple hydrogen atoms can be substituted to form a host of derivatives containing similar functional groups to those above, e.g. saturated and unsaturated aliphatic chains, amino, carboxylic acidic, halogeno, nitro, and sulphonic acid groups as shown in Table 3.6. 

The chemical reactions of sulphonyl nitrenes include hydrogen abstraction, insertion into aliphatic C—H bonds, aromatic substitution , addition to olefinic double bonds, trapping reactions with suitable nucleophiles, and Wolff-type rearrangement. Hydrogen-abstraction from saturated carbon atoms is usually considered to be a reaction typical of triplet... 

Oxidative attack on a carbon-hydrogen bond of an alkyl group a to a nitrogen atom is not restricted to saturated aliphatic amines. In fact X in an X-N-CH- structural subunit can be virtually any common atomic grouping that can be found in stable organic molecules. For example, w-carbon hydrogens of Aralkyl-substituted aromatic cyclic amines (119), aryl amines (120), amides (121), amidines (122), A-nitrosodialkylamines (123), etc. are all subject to oxidative attack, carbinolamine formation, and in most cases release of an aldehyde or ketone depending on the substitution pattern (1° or 2°)... 

If an aromatic compound contains saturated aliphatic side chains nitration carried out under the above conditions takes place always in the benzene nucleus and not in the side chain. Since the carbon atoms of benzene are each united directly to only one hydrogen atom, the nitro-derivatives obtained are tertiary and therefore incapable of forming salts, nitrolic acids, or pseudonitroles, as do the primary and secondary nitro-compounds. 

The carbenes derived from six- [20-22] and seven-membered heterocycles [22-24, 70] of type 14 can be obtained both with an aliphatic or an aromatic backbone. The characteristic NMR resonances for the C2 carbon atoms in six-membered carbene heterocycles (8 236-248 ppm) [20, 21] have been recorded in the same range as the Ccarbene resonances for saturated imidazolidin-2-ylidenes of type 7. Dimerization to enetetramines occurs for some carbenes derived from a six-membered heterocycle [21] and this behavior is independent from the nature of the backbone (saturated or unsaturated), but depends strongly on the steric bulk of the N,N -substituents. 

The lipidated a-amino acids (e.g., 2) are nonnatural a-amino acids with long aliphatic side chains covalently attached to the Ca-carbon. 130 The side chains are saturated or unsaturated, and vary in the total number of carbon atoms (8 to 24), as shown with a few examples in Scheme 11. These amino adds possess the peculiar dual nature of amphiphiles,... 

Hydrocarbons. Compounds consisting of carbon and hydrogen. The number of such compounds is immense and they may be classified into aliphatic (alicyclic) and aromatic (cyclic) compounds. In the former class, the principal carbon atoms are arranged in chains, while in the latter class they are arranged in one or several rings. Hydrocarbons may also be divided into saturated —in which all four valences of C are satisfied, and unsaturated —in which there are one or more double or triple bonds between carbon atoms... 

The organic radicals are produced essentially by one of the following methods Aliphatic carbon-centered radicals are formed mainly from saturated aliphatic compounds via hydrogen atom abstraction by OH and H radicals ( H radicals react with solutes to produce the same radicals as OH radicals, but the rate constants are usually considerably smaller (7)) ... 

---